1 #include <trace/syscall.h> 2 #include <trace/events/syscalls.h> 3 #include <linux/syscalls.h> 4 #include <linux/slab.h> 5 #include <linux/kernel.h> 6 #include <linux/module.h> /* for MODULE_NAME_LEN via KSYM_SYMBOL_LEN */ 7 #include <linux/ftrace.h> 8 #include <linux/perf_event.h> 9 #include <asm/syscall.h> 10 11 #include "trace_output.h" 12 #include "trace.h" 13 14 static DEFINE_MUTEX(syscall_trace_lock); 15 16 static int syscall_enter_register(struct ftrace_event_call *event, 17 enum trace_reg type, void *data); 18 static int syscall_exit_register(struct ftrace_event_call *event, 19 enum trace_reg type, void *data); 20 21 static struct list_head * 22 syscall_get_enter_fields(struct ftrace_event_call *call) 23 { 24 struct syscall_metadata *entry = call->data; 25 26 return &entry->enter_fields; 27 } 28 29 extern struct syscall_metadata *__start_syscalls_metadata[]; 30 extern struct syscall_metadata *__stop_syscalls_metadata[]; 31 32 static struct syscall_metadata **syscalls_metadata; 33 34 #ifndef ARCH_HAS_SYSCALL_MATCH_SYM_NAME 35 static inline bool arch_syscall_match_sym_name(const char *sym, const char *name) 36 { 37 /* 38 * Only compare after the "sys" prefix. Archs that use 39 * syscall wrappers may have syscalls symbols aliases prefixed 40 * with ".SyS" or ".sys" instead of "sys", leading to an unwanted 41 * mismatch. 42 */ 43 return !strcmp(sym + 3, name + 3); 44 } 45 #endif 46 47 #ifdef ARCH_TRACE_IGNORE_COMPAT_SYSCALLS 48 /* 49 * Some architectures that allow for 32bit applications 50 * to run on a 64bit kernel, do not map the syscalls for 51 * the 32bit tasks the same as they do for 64bit tasks. 52 * 53 * *cough*x86*cough* 54 * 55 * In such a case, instead of reporting the wrong syscalls, 56 * simply ignore them. 57 * 58 * For an arch to ignore the compat syscalls it needs to 59 * define ARCH_TRACE_IGNORE_COMPAT_SYSCALLS as well as 60 * define the function arch_trace_is_compat_syscall() to let 61 * the tracing system know that it should ignore it. 62 */ 63 static int 64 trace_get_syscall_nr(struct task_struct *task, struct pt_regs *regs) 65 { 66 if (unlikely(arch_trace_is_compat_syscall(regs))) 67 return -1; 68 69 return syscall_get_nr(task, regs); 70 } 71 #else 72 static inline int 73 trace_get_syscall_nr(struct task_struct *task, struct pt_regs *regs) 74 { 75 return syscall_get_nr(task, regs); 76 } 77 #endif /* ARCH_TRACE_IGNORE_COMPAT_SYSCALLS */ 78 79 static __init struct syscall_metadata * 80 find_syscall_meta(unsigned long syscall) 81 { 82 struct syscall_metadata **start; 83 struct syscall_metadata **stop; 84 char str[KSYM_SYMBOL_LEN]; 85 86 87 start = __start_syscalls_metadata; 88 stop = __stop_syscalls_metadata; 89 kallsyms_lookup(syscall, NULL, NULL, NULL, str); 90 91 if (arch_syscall_match_sym_name(str, "sys_ni_syscall")) 92 return NULL; 93 94 for ( ; start < stop; start++) { 95 if ((*start)->name && arch_syscall_match_sym_name(str, (*start)->name)) 96 return *start; 97 } 98 return NULL; 99 } 100 101 static struct syscall_metadata *syscall_nr_to_meta(int nr) 102 { 103 if (!syscalls_metadata || nr >= NR_syscalls || nr < 0) 104 return NULL; 105 106 return syscalls_metadata[nr]; 107 } 108 109 static enum print_line_t 110 print_syscall_enter(struct trace_iterator *iter, int flags, 111 struct trace_event *event) 112 { 113 struct trace_seq *s = &iter->seq; 114 struct trace_entry *ent = iter->ent; 115 struct syscall_trace_enter *trace; 116 struct syscall_metadata *entry; 117 int i, ret, syscall; 118 119 trace = (typeof(trace))ent; 120 syscall = trace->nr; 121 entry = syscall_nr_to_meta(syscall); 122 123 if (!entry) 124 goto end; 125 126 if (entry->enter_event->event.type != ent->type) { 127 WARN_ON_ONCE(1); 128 goto end; 129 } 130 131 ret = trace_seq_printf(s, "%s(", entry->name); 132 if (!ret) 133 return TRACE_TYPE_PARTIAL_LINE; 134 135 for (i = 0; i < entry->nb_args; i++) { 136 /* parameter types */ 137 if (trace_flags & TRACE_ITER_VERBOSE) { 138 ret = trace_seq_printf(s, "%s ", entry->types[i]); 139 if (!ret) 140 return TRACE_TYPE_PARTIAL_LINE; 141 } 142 /* parameter values */ 143 ret = trace_seq_printf(s, "%s: %lx%s", entry->args[i], 144 trace->args[i], 145 i == entry->nb_args - 1 ? "" : ", "); 146 if (!ret) 147 return TRACE_TYPE_PARTIAL_LINE; 148 } 149 150 ret = trace_seq_putc(s, ')'); 151 if (!ret) 152 return TRACE_TYPE_PARTIAL_LINE; 153 154 end: 155 ret = trace_seq_putc(s, '\n'); 156 if (!ret) 157 return TRACE_TYPE_PARTIAL_LINE; 158 159 return TRACE_TYPE_HANDLED; 160 } 161 162 static enum print_line_t 163 print_syscall_exit(struct trace_iterator *iter, int flags, 164 struct trace_event *event) 165 { 166 struct trace_seq *s = &iter->seq; 167 struct trace_entry *ent = iter->ent; 168 struct syscall_trace_exit *trace; 169 int syscall; 170 struct syscall_metadata *entry; 171 int ret; 172 173 trace = (typeof(trace))ent; 174 syscall = trace->nr; 175 entry = syscall_nr_to_meta(syscall); 176 177 if (!entry) { 178 trace_seq_putc(s, '\n'); 179 return TRACE_TYPE_HANDLED; 180 } 181 182 if (entry->exit_event->event.type != ent->type) { 183 WARN_ON_ONCE(1); 184 return TRACE_TYPE_UNHANDLED; 185 } 186 187 ret = trace_seq_printf(s, "%s -> 0x%lx\n", entry->name, 188 trace->ret); 189 if (!ret) 190 return TRACE_TYPE_PARTIAL_LINE; 191 192 return TRACE_TYPE_HANDLED; 193 } 194 195 extern char *__bad_type_size(void); 196 197 #define SYSCALL_FIELD(type, name) \ 198 sizeof(type) != sizeof(trace.name) ? \ 199 __bad_type_size() : \ 200 #type, #name, offsetof(typeof(trace), name), \ 201 sizeof(trace.name), is_signed_type(type) 202 203 static 204 int __set_enter_print_fmt(struct syscall_metadata *entry, char *buf, int len) 205 { 206 int i; 207 int pos = 0; 208 209 /* When len=0, we just calculate the needed length */ 210 #define LEN_OR_ZERO (len ? len - pos : 0) 211 212 pos += snprintf(buf + pos, LEN_OR_ZERO, "\""); 213 for (i = 0; i < entry->nb_args; i++) { 214 pos += snprintf(buf + pos, LEN_OR_ZERO, "%s: 0x%%0%zulx%s", 215 entry->args[i], sizeof(unsigned long), 216 i == entry->nb_args - 1 ? "" : ", "); 217 } 218 pos += snprintf(buf + pos, LEN_OR_ZERO, "\""); 219 220 for (i = 0; i < entry->nb_args; i++) { 221 pos += snprintf(buf + pos, LEN_OR_ZERO, 222 ", ((unsigned long)(REC->%s))", entry->args[i]); 223 } 224 225 #undef LEN_OR_ZERO 226 227 /* return the length of print_fmt */ 228 return pos; 229 } 230 231 static int set_syscall_print_fmt(struct ftrace_event_call *call) 232 { 233 char *print_fmt; 234 int len; 235 struct syscall_metadata *entry = call->data; 236 237 if (entry->enter_event != call) { 238 call->print_fmt = "\"0x%lx\", REC->ret"; 239 return 0; 240 } 241 242 /* First: called with 0 length to calculate the needed length */ 243 len = __set_enter_print_fmt(entry, NULL, 0); 244 245 print_fmt = kmalloc(len + 1, GFP_KERNEL); 246 if (!print_fmt) 247 return -ENOMEM; 248 249 /* Second: actually write the @print_fmt */ 250 __set_enter_print_fmt(entry, print_fmt, len + 1); 251 call->print_fmt = print_fmt; 252 253 return 0; 254 } 255 256 static void free_syscall_print_fmt(struct ftrace_event_call *call) 257 { 258 struct syscall_metadata *entry = call->data; 259 260 if (entry->enter_event == call) 261 kfree(call->print_fmt); 262 } 263 264 static int __init syscall_enter_define_fields(struct ftrace_event_call *call) 265 { 266 struct syscall_trace_enter trace; 267 struct syscall_metadata *meta = call->data; 268 int ret; 269 int i; 270 int offset = offsetof(typeof(trace), args); 271 272 ret = trace_define_field(call, SYSCALL_FIELD(int, nr), FILTER_OTHER); 273 if (ret) 274 return ret; 275 276 for (i = 0; i < meta->nb_args; i++) { 277 ret = trace_define_field(call, meta->types[i], 278 meta->args[i], offset, 279 sizeof(unsigned long), 0, 280 FILTER_OTHER); 281 offset += sizeof(unsigned long); 282 } 283 284 return ret; 285 } 286 287 static int __init syscall_exit_define_fields(struct ftrace_event_call *call) 288 { 289 struct syscall_trace_exit trace; 290 int ret; 291 292 ret = trace_define_field(call, SYSCALL_FIELD(int, nr), FILTER_OTHER); 293 if (ret) 294 return ret; 295 296 ret = trace_define_field(call, SYSCALL_FIELD(long, ret), 297 FILTER_OTHER); 298 299 return ret; 300 } 301 302 static void ftrace_syscall_enter(void *data, struct pt_regs *regs, long id) 303 { 304 struct trace_array *tr = data; 305 struct syscall_trace_enter *entry; 306 struct syscall_metadata *sys_data; 307 struct ring_buffer_event *event; 308 struct ring_buffer *buffer; 309 unsigned long irq_flags; 310 int pc; 311 int syscall_nr; 312 int size; 313 314 syscall_nr = trace_get_syscall_nr(current, regs); 315 if (syscall_nr < 0) 316 return; 317 if (!test_bit(syscall_nr, tr->enabled_enter_syscalls)) 318 return; 319 320 sys_data = syscall_nr_to_meta(syscall_nr); 321 if (!sys_data) 322 return; 323 324 size = sizeof(*entry) + sizeof(unsigned long) * sys_data->nb_args; 325 326 local_save_flags(irq_flags); 327 pc = preempt_count(); 328 329 buffer = tr->trace_buffer.buffer; 330 event = trace_buffer_lock_reserve(buffer, 331 sys_data->enter_event->event.type, size, irq_flags, pc); 332 if (!event) 333 return; 334 335 entry = ring_buffer_event_data(event); 336 entry->nr = syscall_nr; 337 syscall_get_arguments(current, regs, 0, sys_data->nb_args, entry->args); 338 339 if (!filter_current_check_discard(buffer, sys_data->enter_event, 340 entry, event)) 341 trace_current_buffer_unlock_commit(buffer, event, 342 irq_flags, pc); 343 } 344 345 static void ftrace_syscall_exit(void *data, struct pt_regs *regs, long ret) 346 { 347 struct trace_array *tr = data; 348 struct syscall_trace_exit *entry; 349 struct syscall_metadata *sys_data; 350 struct ring_buffer_event *event; 351 struct ring_buffer *buffer; 352 unsigned long irq_flags; 353 int pc; 354 int syscall_nr; 355 356 syscall_nr = trace_get_syscall_nr(current, regs); 357 if (syscall_nr < 0) 358 return; 359 if (!test_bit(syscall_nr, tr->enabled_exit_syscalls)) 360 return; 361 362 sys_data = syscall_nr_to_meta(syscall_nr); 363 if (!sys_data) 364 return; 365 366 local_save_flags(irq_flags); 367 pc = preempt_count(); 368 369 buffer = tr->trace_buffer.buffer; 370 event = trace_buffer_lock_reserve(buffer, 371 sys_data->exit_event->event.type, sizeof(*entry), 372 irq_flags, pc); 373 if (!event) 374 return; 375 376 entry = ring_buffer_event_data(event); 377 entry->nr = syscall_nr; 378 entry->ret = syscall_get_return_value(current, regs); 379 380 if (!filter_current_check_discard(buffer, sys_data->exit_event, 381 entry, event)) 382 trace_current_buffer_unlock_commit(buffer, event, 383 irq_flags, pc); 384 } 385 386 static int reg_event_syscall_enter(struct ftrace_event_file *file, 387 struct ftrace_event_call *call) 388 { 389 struct trace_array *tr = file->tr; 390 int ret = 0; 391 int num; 392 393 num = ((struct syscall_metadata *)call->data)->syscall_nr; 394 if (WARN_ON_ONCE(num < 0 || num >= NR_syscalls)) 395 return -ENOSYS; 396 mutex_lock(&syscall_trace_lock); 397 if (!tr->sys_refcount_enter) 398 ret = register_trace_sys_enter(ftrace_syscall_enter, tr); 399 if (!ret) { 400 set_bit(num, tr->enabled_enter_syscalls); 401 tr->sys_refcount_enter++; 402 } 403 mutex_unlock(&syscall_trace_lock); 404 return ret; 405 } 406 407 static void unreg_event_syscall_enter(struct ftrace_event_file *file, 408 struct ftrace_event_call *call) 409 { 410 struct trace_array *tr = file->tr; 411 int num; 412 413 num = ((struct syscall_metadata *)call->data)->syscall_nr; 414 if (WARN_ON_ONCE(num < 0 || num >= NR_syscalls)) 415 return; 416 mutex_lock(&syscall_trace_lock); 417 tr->sys_refcount_enter--; 418 clear_bit(num, tr->enabled_enter_syscalls); 419 if (!tr->sys_refcount_enter) 420 unregister_trace_sys_enter(ftrace_syscall_enter, tr); 421 mutex_unlock(&syscall_trace_lock); 422 } 423 424 static int reg_event_syscall_exit(struct ftrace_event_file *file, 425 struct ftrace_event_call *call) 426 { 427 struct trace_array *tr = file->tr; 428 int ret = 0; 429 int num; 430 431 num = ((struct syscall_metadata *)call->data)->syscall_nr; 432 if (WARN_ON_ONCE(num < 0 || num >= NR_syscalls)) 433 return -ENOSYS; 434 mutex_lock(&syscall_trace_lock); 435 if (!tr->sys_refcount_exit) 436 ret = register_trace_sys_exit(ftrace_syscall_exit, tr); 437 if (!ret) { 438 set_bit(num, tr->enabled_exit_syscalls); 439 tr->sys_refcount_exit++; 440 } 441 mutex_unlock(&syscall_trace_lock); 442 return ret; 443 } 444 445 static void unreg_event_syscall_exit(struct ftrace_event_file *file, 446 struct ftrace_event_call *call) 447 { 448 struct trace_array *tr = file->tr; 449 int num; 450 451 num = ((struct syscall_metadata *)call->data)->syscall_nr; 452 if (WARN_ON_ONCE(num < 0 || num >= NR_syscalls)) 453 return; 454 mutex_lock(&syscall_trace_lock); 455 tr->sys_refcount_exit--; 456 clear_bit(num, tr->enabled_exit_syscalls); 457 if (!tr->sys_refcount_exit) 458 unregister_trace_sys_exit(ftrace_syscall_exit, tr); 459 mutex_unlock(&syscall_trace_lock); 460 } 461 462 static int init_syscall_trace(struct ftrace_event_call *call) 463 { 464 int id; 465 int num; 466 467 num = ((struct syscall_metadata *)call->data)->syscall_nr; 468 if (num < 0 || num >= NR_syscalls) { 469 pr_debug("syscall %s metadata not mapped, disabling ftrace event\n", 470 ((struct syscall_metadata *)call->data)->name); 471 return -ENOSYS; 472 } 473 474 if (set_syscall_print_fmt(call) < 0) 475 return -ENOMEM; 476 477 id = trace_event_raw_init(call); 478 479 if (id < 0) { 480 free_syscall_print_fmt(call); 481 return id; 482 } 483 484 return id; 485 } 486 487 struct trace_event_functions enter_syscall_print_funcs = { 488 .trace = print_syscall_enter, 489 }; 490 491 struct trace_event_functions exit_syscall_print_funcs = { 492 .trace = print_syscall_exit, 493 }; 494 495 struct ftrace_event_class __refdata event_class_syscall_enter = { 496 .system = "syscalls", 497 .reg = syscall_enter_register, 498 .define_fields = syscall_enter_define_fields, 499 .get_fields = syscall_get_enter_fields, 500 .raw_init = init_syscall_trace, 501 }; 502 503 struct ftrace_event_class __refdata event_class_syscall_exit = { 504 .system = "syscalls", 505 .reg = syscall_exit_register, 506 .define_fields = syscall_exit_define_fields, 507 .fields = LIST_HEAD_INIT(event_class_syscall_exit.fields), 508 .raw_init = init_syscall_trace, 509 }; 510 511 unsigned long __init __weak arch_syscall_addr(int nr) 512 { 513 return (unsigned long)sys_call_table[nr]; 514 } 515 516 static int __init init_ftrace_syscalls(void) 517 { 518 struct syscall_metadata *meta; 519 unsigned long addr; 520 int i; 521 522 syscalls_metadata = kcalloc(NR_syscalls, sizeof(*syscalls_metadata), 523 GFP_KERNEL); 524 if (!syscalls_metadata) { 525 WARN_ON(1); 526 return -ENOMEM; 527 } 528 529 for (i = 0; i < NR_syscalls; i++) { 530 addr = arch_syscall_addr(i); 531 meta = find_syscall_meta(addr); 532 if (!meta) 533 continue; 534 535 meta->syscall_nr = i; 536 syscalls_metadata[i] = meta; 537 } 538 539 return 0; 540 } 541 early_initcall(init_ftrace_syscalls); 542 543 #ifdef CONFIG_PERF_EVENTS 544 545 static DECLARE_BITMAP(enabled_perf_enter_syscalls, NR_syscalls); 546 static DECLARE_BITMAP(enabled_perf_exit_syscalls, NR_syscalls); 547 static int sys_perf_refcount_enter; 548 static int sys_perf_refcount_exit; 549 550 static void perf_syscall_enter(void *ignore, struct pt_regs *regs, long id) 551 { 552 struct syscall_metadata *sys_data; 553 struct syscall_trace_enter *rec; 554 struct hlist_head *head; 555 int syscall_nr; 556 int rctx; 557 int size; 558 559 syscall_nr = trace_get_syscall_nr(current, regs); 560 if (syscall_nr < 0) 561 return; 562 if (!test_bit(syscall_nr, enabled_perf_enter_syscalls)) 563 return; 564 565 sys_data = syscall_nr_to_meta(syscall_nr); 566 if (!sys_data) 567 return; 568 569 head = this_cpu_ptr(sys_data->enter_event->perf_events); 570 if (hlist_empty(head)) 571 return; 572 573 /* get the size after alignment with the u32 buffer size field */ 574 size = sizeof(unsigned long) * sys_data->nb_args + sizeof(*rec); 575 size = ALIGN(size + sizeof(u32), sizeof(u64)); 576 size -= sizeof(u32); 577 578 rec = (struct syscall_trace_enter *)perf_trace_buf_prepare(size, 579 sys_data->enter_event->event.type, regs, &rctx); 580 if (!rec) 581 return; 582 583 rec->nr = syscall_nr; 584 syscall_get_arguments(current, regs, 0, sys_data->nb_args, 585 (unsigned long *)&rec->args); 586 perf_trace_buf_submit(rec, size, rctx, 0, 1, regs, head, NULL); 587 } 588 589 static int perf_sysenter_enable(struct ftrace_event_call *call) 590 { 591 int ret = 0; 592 int num; 593 594 num = ((struct syscall_metadata *)call->data)->syscall_nr; 595 596 mutex_lock(&syscall_trace_lock); 597 if (!sys_perf_refcount_enter) 598 ret = register_trace_sys_enter(perf_syscall_enter, NULL); 599 if (ret) { 600 pr_info("event trace: Could not activate" 601 "syscall entry trace point"); 602 } else { 603 set_bit(num, enabled_perf_enter_syscalls); 604 sys_perf_refcount_enter++; 605 } 606 mutex_unlock(&syscall_trace_lock); 607 return ret; 608 } 609 610 static void perf_sysenter_disable(struct ftrace_event_call *call) 611 { 612 int num; 613 614 num = ((struct syscall_metadata *)call->data)->syscall_nr; 615 616 mutex_lock(&syscall_trace_lock); 617 sys_perf_refcount_enter--; 618 clear_bit(num, enabled_perf_enter_syscalls); 619 if (!sys_perf_refcount_enter) 620 unregister_trace_sys_enter(perf_syscall_enter, NULL); 621 mutex_unlock(&syscall_trace_lock); 622 } 623 624 static void perf_syscall_exit(void *ignore, struct pt_regs *regs, long ret) 625 { 626 struct syscall_metadata *sys_data; 627 struct syscall_trace_exit *rec; 628 struct hlist_head *head; 629 int syscall_nr; 630 int rctx; 631 int size; 632 633 syscall_nr = trace_get_syscall_nr(current, regs); 634 if (syscall_nr < 0) 635 return; 636 if (!test_bit(syscall_nr, enabled_perf_exit_syscalls)) 637 return; 638 639 sys_data = syscall_nr_to_meta(syscall_nr); 640 if (!sys_data) 641 return; 642 643 head = this_cpu_ptr(sys_data->exit_event->perf_events); 644 if (hlist_empty(head)) 645 return; 646 647 /* We can probably do that at build time */ 648 size = ALIGN(sizeof(*rec) + sizeof(u32), sizeof(u64)); 649 size -= sizeof(u32); 650 651 rec = (struct syscall_trace_exit *)perf_trace_buf_prepare(size, 652 sys_data->exit_event->event.type, regs, &rctx); 653 if (!rec) 654 return; 655 656 rec->nr = syscall_nr; 657 rec->ret = syscall_get_return_value(current, regs); 658 perf_trace_buf_submit(rec, size, rctx, 0, 1, regs, head, NULL); 659 } 660 661 static int perf_sysexit_enable(struct ftrace_event_call *call) 662 { 663 int ret = 0; 664 int num; 665 666 num = ((struct syscall_metadata *)call->data)->syscall_nr; 667 668 mutex_lock(&syscall_trace_lock); 669 if (!sys_perf_refcount_exit) 670 ret = register_trace_sys_exit(perf_syscall_exit, NULL); 671 if (ret) { 672 pr_info("event trace: Could not activate" 673 "syscall exit trace point"); 674 } else { 675 set_bit(num, enabled_perf_exit_syscalls); 676 sys_perf_refcount_exit++; 677 } 678 mutex_unlock(&syscall_trace_lock); 679 return ret; 680 } 681 682 static void perf_sysexit_disable(struct ftrace_event_call *call) 683 { 684 int num; 685 686 num = ((struct syscall_metadata *)call->data)->syscall_nr; 687 688 mutex_lock(&syscall_trace_lock); 689 sys_perf_refcount_exit--; 690 clear_bit(num, enabled_perf_exit_syscalls); 691 if (!sys_perf_refcount_exit) 692 unregister_trace_sys_exit(perf_syscall_exit, NULL); 693 mutex_unlock(&syscall_trace_lock); 694 } 695 696 #endif /* CONFIG_PERF_EVENTS */ 697 698 static int syscall_enter_register(struct ftrace_event_call *event, 699 enum trace_reg type, void *data) 700 { 701 struct ftrace_event_file *file = data; 702 703 switch (type) { 704 case TRACE_REG_REGISTER: 705 return reg_event_syscall_enter(file, event); 706 case TRACE_REG_UNREGISTER: 707 unreg_event_syscall_enter(file, event); 708 return 0; 709 710 #ifdef CONFIG_PERF_EVENTS 711 case TRACE_REG_PERF_REGISTER: 712 return perf_sysenter_enable(event); 713 case TRACE_REG_PERF_UNREGISTER: 714 perf_sysenter_disable(event); 715 return 0; 716 case TRACE_REG_PERF_OPEN: 717 case TRACE_REG_PERF_CLOSE: 718 case TRACE_REG_PERF_ADD: 719 case TRACE_REG_PERF_DEL: 720 return 0; 721 #endif 722 } 723 return 0; 724 } 725 726 static int syscall_exit_register(struct ftrace_event_call *event, 727 enum trace_reg type, void *data) 728 { 729 struct ftrace_event_file *file = data; 730 731 switch (type) { 732 case TRACE_REG_REGISTER: 733 return reg_event_syscall_exit(file, event); 734 case TRACE_REG_UNREGISTER: 735 unreg_event_syscall_exit(file, event); 736 return 0; 737 738 #ifdef CONFIG_PERF_EVENTS 739 case TRACE_REG_PERF_REGISTER: 740 return perf_sysexit_enable(event); 741 case TRACE_REG_PERF_UNREGISTER: 742 perf_sysexit_disable(event); 743 return 0; 744 case TRACE_REG_PERF_OPEN: 745 case TRACE_REG_PERF_CLOSE: 746 case TRACE_REG_PERF_ADD: 747 case TRACE_REG_PERF_DEL: 748 return 0; 749 #endif 750 } 751 return 0; 752 } 753